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View Full Version : Diagnostic Trouble Code P1406, erratic idle, HELP?!?!



sockjock
04-02-08, 03:46 PM
My 95 Blazer just started idling very erratic last night and then the SES light came on. So this morning when Advance opened I went up there and let them put their scan tool on it. It showed a DTC of P1406. Of course they had no clue and so I called a local mechanic who is supposed to be one of the best GM mechanics in the area. He told me he was booked up and wouldn't be able to get to it right away(translation DAYS) But he suggested that the EGR most probably was stuck, but he mentioned that another symptom of this is a hard brake pedal. My brake pedal pressure seems normal but it idles terrible and acts like it wants to stall. I'm stuck in a tight spot. My other Blazer is getting the trans. rebuilt. I need this Blazer on the road since it is my families only mode of transport right now. I could really use some help here(YESTERDAY if possible). I plan on pulling the EGR and checking it, but if that isn't it IDK....HELP.

ps. I recently replaced the fuel pump,relay,sending unit & filter if that's of any help and my mileage is approx. 115,xxx miles.

Mikz86TA
04-02-08, 05:23 PM
Some info :
http://www.obd-codes.com/forums/1116-obd-codes-need-help-p0300-amp-p1406-codes-on-95-blazer.html

sockjock
04-02-08, 07:33 PM
Problem solved. EGR valve was stuck. Thanks for all the info.

bespurcell
04-02-08, 07:41 PM
Glad to hear it.

BigTruckDrivah
04-02-08, 07:52 PM
How can you tell if the EGR is stuck?

sockjock
04-02-08, 08:26 PM
Remove and inspect the valve. Operate the valve open and close by hand. Only way I know.

Jay-Sliver
04-02-08, 09:42 PM
tha6ts correct. you should be able to squeeze the diaphram in the valve against spring pressure, and plug the vaccuum port. the valve should hold its position while the vaccuum port is plugged, and return to "neutral" when you let ur finger off the port. Operation should be smooth, not jerky and studdery..if thats even a word..lol Can clean it out with a throttlebody cleaner through the inlet/outlet port.

Mikz86TA
04-03-08, 01:55 AM
No problem. Glad you found it out =)